Motor fuel



Patented Dec. 16, 1952 UNITED STATES PATENT OFFICE 'Gla'ssboro, N. J., assignors to Socony-Vacuum Oil Company, Incorporated, a corporation 50f New York NoDrawing, Application October 19, 1949, Serial'No. 122,353

-Claims.

This invention relates; broadly, to motor fuels which normally tend to form gum, :and it is more particularly concerned with increasingathe oxidation stabllity thereof.

.tA's is well known to those :familiar with itheart, virtually all .g'asolines, particularly those manufactured bypyrolytic-processes, such as by crack- .ing'r-and iby polymerization, have a tendency to io'rmpolymeric materialsduring storage. These .I'naterialsare commonly knownas gum. When .present in the gasoline, the gum forms resin-like :deposits in :the :carburetor rand :the intake manifoldgan'd on the valve stems of internal combustion engines. Obviously, such deposits are objectionable, since they decrease the opening efficiency of the engine and endanger the operational life.

The exact nature of the gum-forming materials in gasolines is not well known. It has been found, however, that the use ofantioxidants result in decreased gumiormation. Gum-forming constituents of gasolines may be removed by treatment with acids, such'as sulfuric acid, with clay,- and;the like. -Such processes are disadvan- 'tageous, since they decrease theoctane value of the fuel and increase refining costs. Recently various chemicals, such as phenols, have been proposed as addition agents to. gasolines, for the purpose of increasing the oxidation stability thereof, and as a result, decreasing the gumforming tendencies.

It has now been found that the addition of certain new reaction products to motor fuels ;increases the oxidation stability thereof. It has now been discovered that motor 'fuels containing small amounts of reaction products of certain aliphatic monocarboxylic acids with polyalkylenepolyamines have remarkably improved oxidation properties, and correspondingly less tendency to form gum.

Accordingly, 'it is a broad object of this inventionto providegasolines which have an increased resistance to oxidation and, corre's'pondingly, a reduced tendency'to form'gum. 'Another object isto provide a novel oxidation inhibitor. A particular object is to provide-a novel oxidation inhibitor comprising the reaction product of a polyalkylenepolyamine with an aliphatic monocarboxylic acid. A specific object is to provide a gasoline containing a small amount, suflicient to increase its oxidation stability, of the reaction product of a poly'alkylenepolyamine with certain aliphatic monocarboxylic acids. Other objects and advantages of .the present invention'vvillbecome apparent .to those skilled in the art, from the following detailed description.

Broadly stated, the present invention provides a gasoline which normally tends to form gum containing a minor amount, sufiicient to decrease the gum forming tendencies thereof, of the reaction product obtained by 'reactinganaliphatic monocarboxylic'acid having at least about eight carbon atoms per molecule with apoly'alkylenepolyamine having one more nitrogen atom per molecule than there are alkylene groups in the molecule, in a molar proportion varyingbetween about 1:1, respectively, and about 11::1, re-

spectively, 3: representing 'thenumber of nitrogen atoms in the .polyalkylenepolyamine reactant, and said reaction products as new compositions of matter.

The aliphatic monocarboxylic acid reactant utilized herein is an acid of the fatty acid series containing at least 8 carbon atoms, or its acid anhydride or acid halide. .The aliphatic monocarboxylic acid reactant can be saturated 'or unsaturated, branched-chain or straight-chain. Also, it can contain one or more substituent groups such as halogen, hydroxy, amino, nitro,-or other radicals which do not appreciably interfere with the reaction of said acid with the aforementioned polyalkylenepolyamines. Particular preference is accorded the aliphatic monocarboxylic acid reactants having a carbon chain length of between about 8 and about 24 carbon atoms, However, it is contemplated that the aliphatic monocarboxylic acid employed can contain up to 30 carbon atoms. Non-limiting examples of the aliphatic monocarboxylic acid reactant are caprylic acid; 2-ethyl-hexanoic acid; d-bromo-octanoic acid; caprylic acid anhydride; octanoyl chloride; decanoic acid, undecylenic acid; dodecanoyl bromide; tridecanoic acid; myristic acid; myristoyl bromide; aminomyristic acid; pentadecanoic-acid; 4-ketomyristic acid; 'palmitic acid; 9,10-dibromopalmitic acid, margaricacid; stearic acid; dibromostearicacid; a-chlorostearic acid; 9,10,12,13-tetrabromostearoyl chloride; linoleic acid anhydride; oleic acid; linolenic acid; elaidoyl chloride; dihydroxy'stearic acid; nitrostearic acid; arachidic acid; clupanodonic acid; behenic acid anhydride; IO-ketobehem'c acid; .lignoceric acid; selacholeic acid; cerotic acid; heptacosanoic acid anhydride; montanic acid; melissic acid; and ketotriacontanoic acid. Also utilizable are petroleum naphthenic acids and acids obtained by oxidation of petroleum naphthenic acids and acids obtained by oxidation of petroleum fractions.

In practice, the monocarboxylic acid reactant can be replaced, in part, by other monocarboxylic acids having as few as two carbon atoms, or the anhydrides or acid halides thereof, provided that there remains at least one mol of aliphatic monocarboxylic acid reactant having at least 8 carbon atoms per molecule for each mol of polyalkylenepolyamine reactant. For example, a satisfactory product is obtained, in accordance with this invention when one mol of stearic acid and one mol of butyric acid are reacted with one mol of tetraethylenepentamine.

The polyalkylenepolyamine reactants utilizable herein are those compounds having the structural formula:

wherein R is an alkylene radical, or a hydrocarbon radical-substituted alkylene radical, and n is an integer greater than one, there being no upper limit to the number of alkylene groups in the molecule. It has been found that reaction products of this invention which are produced from dialkylenetriamines, i. e., polyalkylenepolyamine reactants wherein n equals two, impart improved characteristics to gasoline. However, they are not so preferable as those reaction products produced from polyalkylenepolyamine reactants having three or more alkylene groups per molecule. Accordingly, those compounds wherein n is an integer between about three and about six are especially valuable for present purposes. Due to their greater commercial availability, the polyethylenepolyamines are particularly preferred. These compounds have the formula:

wherein n is an integer varying between about twoand about six. In naming the polyalkylenepolyamine reactants, the nitrogen atoms are considered to be attached to the terminal carbon atoms of the main carbon atom chain indicated in each compound name. For example, di-(lmethylamylene)triamine has the structural formula:

one) pentamine; penta-(1,5-dlmethy1amylene) hexamine; di (1 methyl 4 ethylbutylene)- triamine; penta- (1,2-dimethyl- 1 -isopropylethylene) hexamine; tetraoctylenepentamine; tri- (1,4-diethylbutylene) tetramine; tridecylenetetramine tetra- (1,4-dipropylbutylene) pentamine; didodecylenetriamine; tetra-tetradecylenepentamine; penta (1 methyl 4 nonylbutylene)- hexamine; tri- (1,15-dimethylpentadecylene) tetramine; trioctadecylenetetramine; dieicosylenetriamine; di (1,2 dimethyl 14 nonyltetradecylene)triamine; di (1,18 dioctyloctadecylene)triamine; penta (1 methyl 2 benzylethylene) hexamine; tetra- (1-methyl-3-benzylpropylene) -pentamine tri- (l-methyl-l-phenyl- 3 propylpropylene)tetramine; and tetra (1- ethyl-Z-benzylethylene) pentamine.

The polyalkylenepolyamines can be prepared by several methods well known to the art. One well accepted method involves the reaction of ammonia with an alkyl, or substituted alkyl dihalide. For example, tetraethylenepentamine has been produced by reacting ammonia with ethylene bromide.

Test data tend to establish that the first molecule of the monocarboxylic acid reactant which reacts with the polyethylenepolyamine reactant condenses with both a terminal nitrogen atom and the nitrogen atom adjacent thereto, with the formation of two molecules of water, to form an imidazoline ring. The other molecules of the monocarboxylic acid reactant probably react with the remaining nitrogen atoms to form acylated derivatives. No evidence has been found for the presence of more than one imidazoline ring per molecule. The following example furnishes evidence of the imidazoline structure:

EXAMPLE 1 Pure diethylenetriamine (0.5 mol) (51.5 grams) and caprylic acid (0.5 mol) (72 grams) were heated and stirred at 140-150 C. for 11.5 hours, under a benzene reflux. During the course of the reaction, 19.4 milliliters (1.08 mols) of water were removed from the reaction vessel by azeotropic distillation with benzene. The reaction mixture was topped free of benzene. Then. a 100-gram portion of the product was vacuum-distilled. Fraction 3 (25.5 grams), which boiled at 146-149" C. under 1.8 millimeters pressure, had the follow- H! CH:

In numbering the main carbon atom chain, the carbon atom attached to the terminal -NH2 radical is designated as the carbon atom in the 1 position. Similar alkylene groups recur throughout the molecule. Non-limiting examples of the polyalkylenepolyamine reactants are diethylenetriamine; triethylenetetramine; tetraethylenepentamine; di (methylethylene)triamine; hexapropyleneheptamine; tri-(ethylethylene)tetramine; penta (1 methylpropylene) hexamine; tetrabutylenepentamine; hexa- (1,1- dimethylethylene)heptamine; di (1 methylbutylene)triamine; pentaamylenehexamine; tri- (1,2,2-trimethylethylene) tetramine; dil-mething analysis corresponding to the empirical formula of the imidazoline compound:

A sample of Z-methylimidazoline (M. P. 104.54 105 'C.) was prepared in accordance with the method of Ladenberg, Ber., 27, 2952 (1894). This was used as a reference compound.

An infrared spectrum was obtained on a highlyy1amylene)triamine; tetra-(1,3-dimethylpropylrefined white oil dispersion of the reference com-v pound... Another infrared spectrum was obtained for liquid Fraction. 3. The similarity of the two spectra indicated the presence of the imidazoline ring in Fraction 3. On the basis of the results of chemical analyses and of infrared absorption spectra, it is postulated that Fraction 3 has the following structure:

CHCH1 N. N-omomNH,

In a similar manner, it can be postulated that a polypropylenepolyamine reactant will react to form a A -tetrahydropyrimidine ring. For example, the reaction between equimolar quantities of dipropylenetriamineand caprylic acid can produce the product:

(IJ7H15 On the other hand, polyalkylenepolyamine reactantsv having longer alkylene chain lengths probably will not form ring compounds. The reaction products will be acylated, however.

The total number of moles of monocarboxylic acid reactant which is reacted with each mol of polyalkylenepolyamine. reactant must not exceed the total number of nitrogen atoms in the polyalkylenepolyamine reactant. Accordingly, the molar proportion of monocarboxylic acid reactant to polyalkylenepolyamine reactant will vary between about 1:1, respectively, and about 12:1, respectively, :1: representing the number of nitrogen atoms in the polyalkylenepolyamine reactant. However, when using polyethylenepolyamine or polypropylenepolyamine reactants this proportion will vary between about 1:1 and about (:c-llzl, respectively, since two nitrogen atoms apparently react with the first molecule of the monocarboxylic acid reactant to form a ring compound.

For example, when tetraethylenepentamine is utilized as the polyalkylenepolyamine reactant, one, two, three, or even four mols of a monocarboxylic acid reactant can be reacted with each mol thereof, to produce the reaction prod ucts of this invention. If fixed mols of monocarb'oxylic acid reactant are used, theoretically, there would be an unreacted mol of monocarboxylic acid reactant. Such a product is not contemplated to be within the scope of the present invention. It must be strictly understood,

therefore, that the reaction products of this invention are not pure, definite chemical compounds. The available facts indicate that the reaction involved is much more complex. Evidence has been found for the formation of the imidazoline or the A -tetrahydropyrimidine ring. However, the precise manner of reaction of the other mols of the monoca'rboxylic acid reactant is purely conjectural. This is substantiated by the fact that some residual acidity is always present in the reaction product. In view of the foregoing, it will be appreciated that any designation assigned to these products, other than a definition comprising a recitation of the process of producing them, is not accurately descriptive of them.

The-temperature-at which the reaction betweenthe aliphatic monocarboxyli'c acid reactant and the polyalk-ylenepolyamine reactant is. effected varies, generally, between about 60 C. and. about 200 C; the reaction at temperatures varying between about C. and about C.

The time of reaction is dependent on a number of variables, such as the nature of the particular reactants employed, the molar ratio of the reactants, and the temperature of reaction. In practice, the reaction is continued until the formation of water observed during the course of the reaction has substantially ceased. This period" of time is, generally, between about 4 hours and about 16 hours, and, more often, between about 6 hours and about 10 hours.

As noted hereinbefore, water is formed as a by-product of the reaction between the aliphatic monocarboxylic acid reactant and the polyalkyl-v enepolyamine reactant. In order to facilitate the removal of this water, and in order to efiect a more complete reaction, a hydrocarbon solvent which forms an azeotropic mixture with water can be added to the reaction mixture. Heating of the liquid reaction mixturev at the preferred reaction temperature is continued. until the removal of water by azeotropic distillation has substantially ceased. In general, any hydrocarbon solvent which forms an azeotropic mixture with water can be used. It is preferred,

however, to use an aromatic hydrocarbon solventv of the benzene series, such as benzene, toluene, xylene, and the like. The amount of solvent used is a variable and non-critical factor. pendent on the amounts of reactantsemployed and on the reaction temperature selected. An amount of solvent sufficient to support the azeotropic distillation will generally be used, but a large excess must be avoided, since the reaction temperature will be lowered thereby. Water of reaction can also be removed, as the reaction proceeds, by operating under reduced pressure. When operating with a reaction vessel equipped with a reflux condenser provided with a water take-off trap, suflicient reduced pressure can be achieved by applying a slight vacuum to the upper end of the condenser. The pressure inside the system is usually reduced to between about 50 and about 300 millimeters. If desired, water can be removed also from the reaction mixture by distillation at relatively high temperatures.

In the interest of brevity, the reaction products of this invention are best defined by reciting the reactants and the number. of mols of each which are used in the reaction. For example, the reacplated herein are those products produced by re acting the following combinations of reactants: caprylic acid (III)+dieicosylenetriamine (I); 2-ethylhexanoic acid (IV)+tetrabuty1enepentamine (I); u-bromooctanoi'c acid (-I)+tridecylenetetramine (I); caprylic acid anhydride (II)+ hexal,l--dimethylethylene) -hept'amine (I) octanoyl chloride (II)+triethylenetetramine (I);

decanoic acid (I)+pentaamylenehexamine (I); undecylenic acid (II)+tetraoctylenepentamine; dodecanoyl bromide (II) +tetraethylenepentamine (I); tridecanoic acid (I) +diethylenetriamine (I); myristic acid (II)+diethylenetriamine (I): ketotriacontanoic acid (III)"+tetraethyIene- It is preferred, however, to carry out It is de-- pentamine (I);' myristoyl bromide (V) Ihexadipropylbutylene)pentamine (I); palmitic acid (V) +tetra+ (tetradecylene) pentamine (I) selacholeic acid (I) +tri+ (1,15-dimethylpentadecylene)tetramine (I); 9,10-dibromopalmitic acid (II)+dieicosylenetriamine (I); lignoceric acid (I) +di- (1,18-dioctyloctadecylene) -triamine (I) margaric acid (III) +tetra- (1-methyl-3-benzylpropylene)-pentamine (I); l-ketobehenic acid (I) +tetra- (l-ethyl-2- benzylethylene) pentamine (I); stearic acid (III) +triethylenetetramine (I); behenic acid anhydride (I)+di-(methylethylene)triamine (I); dibromostearic acid (I)+tri (ethylethylene)tetramine (I); clupanodonic acid (II) +tetrabutylenepentamine (I) a chlorostearic acid (I) +di- (l-methylbutylene) triamine (I); arachidic acid (IV) +pentaamy1enehexamine (I); 9,10,12,13-tetrabromostearoyl chloride (I)+ di- (l-methylamylene) triamine (I) nitrostearic acid (II) +penta- (1,5- dimethylamylene) -hexamine (I); linoleic acid anhydride (II)|-penta- (1,2 dimethyl l isopropylethylene) hexamine (I); dihydroxystearic acid (I)+tri-(l,4-diethylbuty1ene)tetramine (I); oleic acid (IV) +tridecylenetetramine (I); elaidoyl chloride (III) didodecylenetriamine (I); and linolenic acid (I) +trioctadecylenetetramine (I).

The amount of the afore-described reaction products used as antioxidants is generally a function of the specific product being employed and of the nature of the gasoline used, i. e., its gumforming tendency. Ordinarily, the amount employed is between about 0.0001 and about 1 per cent by weight, and preferably between about 0.001 and about 0.01 per cent, by weight. In addition to the afore-described reaction products, the gasolines of this invention can contain minor amounts of other materials, such as coloring matter, diluents, antiknock additives, and the like.

The following specific examples are for the purpose of illustrating the present invention, and of demonstrating the advantages thereof. It must be strictly understood that this invention is not to be limited to the particular reactants, and molar proportions employed, or to the operations and manipulations set forth therein. As those skilled in the art will readily understand, a wide variety of other reactants and molar proportions can be used, as set forth hereinbefore.

EXAMPLE2 Stearic acid (I) +tetraethylenepentamine (I) Stearic acid (28.5 grams) (0.1 mol) and tetraethylenepentamine (18.9 grams) (0.1 mol) were weighed into a reaction vessel provided with a stirrer, a thermometer, and a reflux take off trap adapted to collect water produced during the course of the reaction. The flask contents were heated to 150 C. and suflicient benzene was added to permit refluxing at a pot temperature of 150 C. After eight hours of reaction 3.5 milliliters of water were collected. The benzene was removed from the reactants by distillation under reduced pressure at 150 0., leaving as the residue 8.. the desired reaction product. This'product had a neutralization number of 3.4.

EXAMPLE 3 Stearic acid (II) +tetraethylenepentamine (I) One mol (2 84.5 grams) of stearic acid was reacted with 0.53 mol grams) of tetraethylenepentamine in the manner described in Example 2, except that xylene solvent was used at 144-150" C. for 6 hours. A total of 24.2 milliliters of water were collected. The reaction product was isolated as described hereinbefore.

EXAMPLE 4 Stearic acid (III) +tetraethylenepentamine (I) until 6.2 milliliters of water had collected. The

total reaction time was 10.75 hours. The solvent (benzene) was removed from the resulting mixture under reduced pressure at a pot temperature of 145 C. The solid residue thus obtained had a neutralization number of 41.5.

EXAWLE 5 Stearic acid (IV) +tetraethylenepentamine (I) To a reaction vessel provided with a stirrer, a thermometer, and a reflux takeoff trap were added 113.6 grams (0.4 mol) of stearic acid, and 18.9 grams (0.1 mol) of tetraethylenepentamine. The

contents of the vessel were heated to a temperature of -160 C. and sufficient benzene was thereafter added to maintain reflux at this temperature. The total reaction time was 10 hours. The solvent was removed under reduced pressure to yield a solid residual material having a neutralization number of 53.2.

EXAMPLE 6 Stearic acid (I) +triethylenetetramine (I) Stearic acid (113.6 grams) (0.4 mol) and triethylenetetramine (58.4 grams) (0.4 mol) were reacted, as described in Example 2, at 145-150 C. for 8 hours, to yield a product having a neutralization number of 6.1.

EXAMPLE 7 Stearic acid (I)+diethylenetriamine (I) Stearic acid (0.77 mol) (220 grams) was reacted with 0.97 mol (100 grams) of diethylenetriamine in the manner set forth in Example 2, except that xylene reflux was used. A temperature of 144-150 C. was maintained for 7 hours. A total of 32.4 milliliters of water were collected.

EXAMPLE 8 Stearic acid (I) +butyric acid (I) +tetraethylenepentamine (I) 1 Stearic acid (57 grams) (0.2 mol), butyric acid The residual product .9 mixture thus obtained had a neutralization number of 11.11.

EXAMPLE 9 Oleic, acid (I) +tetraethylenepentamine (I) -l e ic acid (28.2 grams) (0.1 mol) and tetraethylenepentamine (18.9 grams) (0.1 mol) were reacted as described in Example 2, at a temperature of 140-150 C. for 8 hours.

EXAMPLE 10 Laurie acid (II) +tetraethylenepentamine (I) Laurie acid (40.0 grams) (0.2 mol) and tetraethylenepentamine (18.9 grams) (0.1 mol) were placed in a reaction vessel equipped as described in Example 2. The flask contents were heated to 145 C. and 'suflicient benzene was added to permit refluxing at that temperature. The reaction was continued for nine hours, and 5.1 milliliters of water were collected. The benzene was removed by distillation at 145 C., under about 100 millimeters pressure. The reaction product thus obtained had a neutralization num- 5 ber of 2.4.

EXAMPLE 11 C'apric acid .(I)+tetraethylenepentamine (I) then placed in a vigorously-boiling water bath.

The time of immersion is noted. The test is continued to the break point, i. e., that point of elapsed time, in minutes, which is preceded by a pressure drop of two pounds per square inch in 15 minutes, and is succeeded by a pressure drop of not less than two pounds per square inch. The total time elapsing between the immersion time and the break point is recorded as the Induction Period. In evaluating gasolines by this test, the gum-forming tendencies are considered to vary inversely with the length of the induc tion period.

In the following four tables are set forth pertinent test data for the reaction products described in the examples. These data are presented in four tables, because the reaction products were evaluated using difierent lots of thermally cracked gasoline.

TABLE I Molar Weight Inducrcent in Example Acid Amine 1 tion pe period amine gasoline A utes 176 SIBQIIQ PA 1 Z 1 0. 004 380 Ole1c TEPA 1:1 .004 262 1 TE' Ais tetraethylenepentamine.

(ASTM Method TABLE II Molar Inducpropor- 2 22 231 5 tion Example Acid Amine 1 tiqrdl, pthermal perio fi gasoline B fig 159 Stearic TETA 1:1 0. 004 300 --do TEPA 2:1 .004 300 Stearic+butyric TEPA 1: 1: 1 004 v .298 Stearic TEPA '3: 1 004 287 1- do TEPA 4:1 .004- 198 do BETA; 71:1 .004 173 (1) DETA is diethylenetriamine.

'TETA is triethylenetetramine. TEPA is tetraethylenepentamme.

TABLE III Molar Induc .propor- Z225 tion Example Acid Amine 1 tion, pthermal period,

acid/ 0 minamine gasolme utes 1 TEPA is tetraethylenepentamine.

TABLE IV Effect of varying concentration ofstearic acid (I) tetraethylenepentamine (I) in thermal gasoline D Molar Weight Inducproper" percentin tion Example Acid Amine Q37 thermal period,

so: nunamine gasolmep utes 1 TEPA is tetraethylenepentamine.

It will be apparent, from the data set forth in the tables, that the addition of small amounts of the reaction products of this invention to thermally cracked gasoline markedly improves the gum-forming characteristics thereof. As will be apparent to those skilled in the art, such improvement will be evident in any gasoline which tends to form gum. Accordingly, although the invention has been illustrated with thermally cracked gasolines, the use of other gasolines is contemplated herein. Thus, the gasoline can be a straight-run gasoline, a catalytically cracked gasoline, or the like.

Further examples of the preparation and utility of the reaction products contemplated herein are set forth in two copending applications of the present inventors. One application, Serial Number 127,278, filed November 14, 1949, now Patent No. 2,568,876 relates to antirust agents produced by reacting a monocarboxylic acid with a polyalkylene-polyamine to produce an intermediate product, and by further reacting this intermediate product with an alkenyl succinic acid anhydride. The other application, Serial Number 115,948, filed September 15, 1949, is concerned with emulsifiable oils containing the reaction product of a polyalkylenepolyamine having between about fourteen and about thirty carbon atoms per molecule.

Although the present invention has been described with preferred embodiments, it is to be 11' understood that modifications and variations may be resorted to without departing from the spirit and scope thereof; as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

.. What is claimed is:

1. A motor ,fuel which comprises a gasoline containing between about 0.0001 per cent and about one per: cent, by weight, of the reaction product obtained by reacting, with the formation of water of condensation, at least one aliphatic monocarboxylic acid with a polyalkylenepolyamine having one more nitrogen atom per molecule than there are alkylene groups in the molecule and having between about two and about six alkylene roups per molecule, in a molar proportion varying between about 1:1, respectively, and about 2:: 1, respectively, as representing the number of nitrogen atoms in the polyalkylenepolyamine molecule, at a temperature of between about 60 C. and about 200 C., and for a period of time varying between about 4 hours and about 16 hours; at least one mole of said aliphatic monocarboxylic acid so reacted with each mole of said polyaLrylenepolyamine having at least about 8 carbon atoms per molecule.

. 2. A motor fuel which comprises a gasoline containing between about 0.0001 per cent and about one per cent, .by-weight, of the reaction product obtained by reacting, with the formation of water of condensation, at least one aliphatic monocarbo-xylic acid with a polyalkylenepolyamine having one more nitrogen atom per molecule than there are alkylene groups in the mole- .cule and having between about two and about .between about 8 carbon atoms and about 24 carbon atoms per molecule.

'3. A motor fuel which com rises a gasoline containing between about 0.0001 per cent and about one per cent, by weight, of the reaction product obtained by reactingwith the formation ,of water of condensation, an aliphatic monocarboxylic acid with a polyethylenepolyamine having one more nitrogen atom per molecule than there are ethylene groups in the molecule and having between about two and about six ethylene grou s per mo ecule, in a molar proportion varying between about 1:1, respectively, and about 7 (:11-1) :1, respectively, :1: representing the number of nitrogen atoms in the polyethylenepolyamine molecule, at a temperature of between about 60 C; and about 200 0., and for a period of time varying between about 4 hours and about 16 hours; at least one mole of said aliphatic monocarboxylic acid so reacted with each mole of said polyethylenepolyamine having between about 8 carbon atoms andabout'24 carbon atoms per molecule.

4. A motor fuel containing between about 0.0001 per cent and about one per cent, by weight, of the reaction .product obtained by reacting, with the formation of water of condensation, an aliphatic monowhich comprises a gasoline 4 "carboxylic acid with {polyethylenepolyamine and about 16 hours; at least one mole of said aliphatic monocarboxylic acid so reacted with each mole of said polyethylenepolyamine having between about 8 carbon atoms and about 24 carbon atoms per molecule.

5. A motor fuel comprising a gasoline containing between about 0.0001 per cent and about one per cent, by weight of the reaction product obtained by reacting, with the formation of water of condensation, stearic acid with a polyethylenepolyamine having one more nitrogen atom per molecule than there are ethylene groups in the molecule and having between about three and about six ethylene groups per molecule, in a molar proportion varying between about 1': 1, respectively, and about (III-1) :1, respectively, 3: representing the number of nitrogen atoms in the polyethylenepolyamine molecule, at a temperature of between about 60 C. and about 200 C'., and for a period of time varying between about 4 hours and about 16 hours.

6. A motor fuel which comprises a gasoline containing between about 0.0001 percent and about one per cent, by weight, of the reaction product obtained by reacting, with the formation of water of condensation, stearic acid with tetraethylenepentamine, in a molar proportion of about 1:1, respectively, at a temperature of between about 60 C. and about 200 C., and for a period of time varying between about 4 hours and about 16 hours.

7. A motor fuel which comprises a gasoline containing between about 0.0001 per cent and about one per cent, by weight, of the reaction product obtained by reacting, with the formation of water of condensation, stearic acid vwith triethylenetetramine, in a molar proportion of about 1:1, respectively, at a temperature of between about 60 C. and about 200 C., and for a period of time varying between about 4 hours and about 16 hours.

8. A motor fuel which comprises a gasoline containing between about 0.0001 per cent and about one per cent, by weight, of the reaction product obtained by reacting, with the formation of water of condensation, stearic acid with tetraethylenepentamine, in a molar proportion of about 3:1, respectively, at a temperature of between about 60 C. and about 200 C., and for a .period of time varying between about 4 hours and about 16 hours.

9. A motor fuel which comprises a gasoline containing between about 0.0001 per cent and about one per cent, by weight, of the reaction product obtained by reacting, with the formation of water of condensation, capric acid with tetraethylenepentamine, in a molar proportion of about 1:1, respectively, at a temperature of between about 60 C. and about 200 0., and for a period of time varying between about 4 hours and about 16 hours.

10. A motor'fuel which comprises a gasoline containing between about 0.0001 per cent and about one per cent, by weight, of the reaction REFERENCES CITED The following references are of record in the file of this patent:

Number 14 UNITED STATES PATENTS Name Date Calcott et a1 Dec. 19, 1933 Neelmeier et a1. Feb. 20, 1934 Faust June 6, 1939 Rosen Sept. 30, 1941' Musselman Dec. 2, 1941 Chenicek Sept. 15, 1942 Dietrich Feb. 23, 1943 Robinson Apr. 4, 1944 

1. A MOTOR FUEL WHICH COMPRISES A GASOLINE CONTAINING BETWEEN ABOUT 0.0001 PER CENT AND ABOUT ONE PER CENT, BY WEIGHT, OF THE REACTION PRODUCT OBTAINED BY REACTING, WITH THE FORMATION OF WATER OF CONDENSATION, AT LEAST ONE ALIPHATIC MONOCARBOXYLIC ACID WITH A POLYALKYLENEPOLYAMINE HAVING ONE MORE NITROGEN ATOM PER MOLECULE THAN THERE ARE ALKYLENE GROUPS IN THE MOLECULE AND HAVING BETWEEN ABOUT TWO AND ABOUT SIX ALKYLENE GROUPS PER MOLECULE IN A MOLAR PROPORTION VARYING BETWEEN ABOUT 1:1, RESPECTIVELY, AND ABOUT X:1, RESPECTIVELY, X REPRESENTING THE NUMBER OF NITROGEN ATOMS IN THE POLYALKYLENEPOLYAMINE MOLECULE, AT A TEMPERATURE OF BETWEEN ABOUT 60* C. AND ABOUT 200* C., AND FOR A PERIOD OF TIME VARYING BETWEEN ABOUT 4 HOURS AND ABOUT 18 HOURS; AT LEAST ONE MOLE OF SAID ALIPHATIC MONOCARBOXYLIC ACID SO REACTED WITH EACH MOLE OF SAID POLYALKYLENEPOLYAMINE HAVING AT LEAST ABOUT 8 CARBON ATOMS PER MOLECLE. 